I found a fix for my situation that had identical symptoms as yours. After tons of Googling and trying numerous suggestions and nearly resorting to a reinstall, I found my problem was SIMPLE! I had noticed that there were some times when I could change a
file/folder and it responded instantly, so I started to observe what was unique. I noticed if I browsed to folders in Windows File Explorer under "This PC", any changes/refreshes worked fine, but if I browsed to the same folders by going into
any folders pinned under "Favorites", they needed to be manually refreshed or revisited. It turns out the problem was the links in Favorites were broken. I copied my user profile in the past during the install of Windows 8 and so some of these links were referencing
the old "Start In" path on the shortcuts. SOLUTION FOR ME: Delete any custom links in Favorites, then browse to the folder in This PC and drag it back to Favorites to create a new, correct link. Works like magic now.
Chris